Internet Protocol (IP) telephony has changed the business model and engineering approaches of how voice services are provisioned and delivered. The attractive economics of IP telephony (stemming largely from the global connectivity and accessibility of the Internet) along with innovative productivity tools for users have triggered adoption of this technology by numerous businesses, organizations, enterprises and the like. Unfortunately, this adoption primarily has been uncoordinated, and driven by the needs of the specific enterprise little regard to a “global” approach for IP telephony deployment. Interestingly, the prevailing IP telephony implementations have confined the particular enterprises, as to make communications outside the enterprise difficult and impractical. Moreover, security concerns are an impediment to wide spread deployment of IP telephony systems.
As enterprises implement Internet telephony as well as messaging systems and associated applications, closed communities of IP enabled users are created—i.e., “IP islands”. That is, because of systems and applications constraints and incompatibilities, these IP enable users are isolated, and thus, cannot readily communicate with each other. Moreover, as Internet Service Providers (ISPs), cable, and mobile network operators begin to provide Internet telephony services. The IP islands grow even larger into a “constellation” of non-connected communities. While such communities can in some cases be linked using the Public Switched Telephone Network (PSTN), the benefits of IP telephony—e.g., user presence, unified communications, user preference, and lower costs may be sacrificed.
Unlike the PSTN in which users and carriers are easily reachable by anyone on the network, IP telephony is subject to several constraints. First, users are required to have knowledge of whether an IP endpoint is available if the full capabilities of IP telephony are to be realized. Also, the knowledge of whether there are multiple IP enabled devices is being used by the called party as well as how to reach such devices is needed. Another constraint is that a single IP “telephone” number is not available among the various IP enabled devices; instead, these devices utilize diverse and complex addresses. Additionally, determining the identity of the calling party (e.g., caller ID) is an important function. Further, IP networks are vulnerable to a variety of security threats, which are non-existent in circuit-switched telephony networks.
Based on the foregoing, there is a clear need for an approach that facilitates securely bridging of the IP islands, thereby enabling greater deployment of IP telephony. There is also a need for a mechanism to ensure compatibility and coordination of IP telephony services among service providers. There is a further need for an approach to exploit the full capabilities of Internet telephony technologies.